Sending & Recieving Text Messages From Website

I need to have an application written that allows people to be notified when a ticket is available. When a ticket becomes available we need to send a text message and then wait XX minutes for a response. They will either respond Yes or No. Yes if they want the ticket or No if they do not want the ticket.

I am wondering what the best API/Gateway would be to accomplish this. It is important that the text message be delivered quickly because the recipient will only have XX minutes to respond before the ticket is released to the next wait listed person.

Any suggestions?

Thank you very much